scholarly journals Combined Solar Thermochemical Solid/Gas Energy Storage Process for Domestic Thermal Applications: Analysis of Global Performance

2019 ◽  
Vol 9 (9) ◽  
pp. 1946 ◽  
Author(s):  
Oleksandr Skrylnyk ◽  
Emilie Courbon ◽  
Nicolas Heymans ◽  
Marc Frère
Keyword(s):  
Energy Storage ◽  
Fixed Bed ◽  
Packed Bed ◽  
Pilot Scale ◽  
Hot Water ◽  
Water Tank ◽  
Atmospheric Conditions ◽  
Storage Process ◽  
Moving Bed ◽  
Global Performance

Thermal energy used below 100 °C for space heating/cooling and hot water preparation is responsible for a big amount of greenhouse gas emissions in the residential sector. The conjecture of thermal solar and thermochemical solid/gas energy storage processes renders the heat generation to become ecologically clean technology. However, until present, few pilot scale installations were developed and tested. The present work is devoted to the experimental study of global performance of a pilot scale thermochemical energy storage prototype. Two working modes, namely fixed packed bed and moving bed, were tested using 2.2 kg and 5.5 kg of composite material (silica gel impregnated with calcium chloride) under indoor atmospheric conditions. The global experimental efficiency of a 49l water tank charging process during 75 min was found as high as 0.8–0.85. The energy storage density reached in the fixed bed mode by the material was 158 kWh/m3, while in the moving bed mode it was 2.5 times lower. The reasons for such a difference are discussed in depth in the text.

Analysis of Thermal Energy Storage to a Combined Heat and Power Plant

2021 ◽  
Vol 9 (9) ◽  
pp. 1313-1320
Author(s):  
Shahim Nisar
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Demand ◽  
Power Plants ◽  
Heat Storage ◽  
Packed Bed ◽  
Water Tank ◽  
Latent Heat Storage ◽  
Storage Methods

Abstract: Thermal energy storage (TES) is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used at a later time for heating and cooling applications and power generation. TES systems are used particularly in buildings and in industrial processes. This paper is focused on TES technologies that provide a way of valorizing solar heat and reducing the energy demand of buildings. The principles of several energy storage methods and calculation of storage capacities are described. Sensible heat storage technologies, including water tank, underground and packed-bed storage methods, are briefly reviewed. Additionally, latent-heat storage systems associated with phase-change materials for use in solar heating/cooling of buildings, solar water heating, heat-pump systems, and concentrating solar power plants as well as thermo-chemical storage are discussed. Finally, cool thermal energy storage is also briefly reviewed and outstanding information on the performance and costs of TES systems are included.

scholarly journals Energy and Exergy Analysis of Sensible Thermal Energy Storage—Hot Water Tank for a Large CHP Plant in Poland

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4842 ◽  
Author(s):  
Ryszard Zwierzchowski ◽  
Marcin Wołowicz
Keyword(s):  
Energy Storage ◽  
Ambient Temperature ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Exergy Analysis ◽  
Hot Water ◽  
Water Tank ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

The paper contains a simplified energy and exergy analysis of pumps and pipelines system integrated with Thermal Energy Storage (TES). The analysis was performed for a combined heat and power plant (CHP) supplying heat to the District Heating System (DHS). The energy and exergy efficiency for the Block Part of the Siekierki CHP Plant in Warsaw was estimated. CHP Plant Siekierki is the largest CHP plant in Poland and the second largest in Europe. The energy and exergy analysis was executed for the three different values of ambient temperature. It is according to operation of the plant in different seasons: winter season (the lowest ambient temperature Tex = −20 °C, i.e., design point conditions), the intermediate season (average ambient temperature Tex = 1 °C), and summer (average ambient temperature Tex = 15 °C). The presented results of the analysis make it possible to identify the places of the greatest exergy destruction in the pumps and pipelines system with TES, and thus give the opportunity to take necessary improvement actions. Detailed results of the energy-exergy analysis show that both the energy consumption and the rate of exergy destruction in relation to the operation of the pumps and pipelines system of the CHP plant with TES for the tank charging and discharging processes are low.

Analysis of Flow Through Packed Bed of Spheres Containing Phase Change Materials for Thermal Energy Storage Applications

2019 ◽  
Author(s):  
Vinit V. Prabhu ◽  
Ethan Languri ◽  
Kashif Nawaz
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Response Time ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Response Rate ◽  
Packed Bed ◽  
Hot Water

Abstract The research on thermal energy storage (TES) systems have received a lot of attention in recent decades for sustainable use of thermal energy in various industrial and residential applications. The existing challenge in designing the TES is the response time of charging and discharging cycles that keeps these systems away from wide utilization in industries. Literature data show that beside the low thermal conductivity of most phase change materials (PCMs) as active media in TES systems, the poor flow distribution may be another factor affecting the response rate. This study aims to considerably reduce the response time by packing the PCMs in a bed of spheres made of high thermal conductivity material. The response rate during the charging cycle is studied numerically by passing hot water at 70 °C over the packed bed of spheres. The numerical analysis is performed using ANSYS Fluent 19. The PCM used in this study is a paraffin and has a melting point of 48 °C. The response rate of the system is studied and it is compared to other similar systems mentioned in literature. The amount of energy storage is also studied by changing the flow rate of water.

scholarly journals Parametric Cost Optimization of Solar Systems with Seasonal Thermal Energy Storage for Buildings

2021 ◽  
Vol 246 ◽  
pp. 03003
Author(s):  
Willy Villasmil ◽  
Marcel Troxler ◽  
Reto Hendry ◽  
Philipp Schuetz ◽  
Jörg Worlitschek
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Cost Optimization ◽  
Hot Water ◽  
Water Tank ◽  
Existing Building ◽  
Solar Systems ◽  
Living Space ◽  
Solar Fraction

In combination with seasonal thermal energy storage (STES), solar energy offers a vast potential for decarbonizing the residential heat supply. In this work, a parametric optimization is conducted to assess the potential of reducing the costs of water-based STES through the use of alternative thermal insulation materials and the integration of an underground storage outside the building. The investigated configurations include: a hot-water tank, a solar collector installation, and a multifamily building with a solar fraction of 100%. The storage is either integrated inside the building or buried underground in its direct vicinity. A simulation-based analysis shows that if the tank is integrated inside an existing building (as part of a retrofitting action) – where costs are primarily driven by the loss of living space – vacuum-insulation panels can lead to significant savings in living space and a cost advantage compared to the use of conventional glass wool. Nevertheless, storage integration inside an existing building is a more expensive option compared to an external integration due to the high costs associated to the internal building modification and loss of living space. Despite the high excavation costs and increased heat losses, the concept of burying the storage underground is a promising option to allow the integration of large-volume seasonal storage systems in new and existing buildings.

Experimental Testing of a Thermoelectric-Based Hydronic Cooling and Heating Device With Transient Charging of Sensible Thermal Energy Storage Water Tank

2008 ◽  
Author(s):  
Michael J. Kazmierczak ◽  
Sreenidhi Krishnamoorthy ◽  
Abhishek Gupta
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Tank ◽  
Hot Water ◽  
System Component ◽  
Water Tank ◽  
Te Modules

Experiments were performed to charge either cold or hot water thermal energy storage tanks using a heat exchanger equipped with multiple thermoelectric (TE) modules. The primary objective was to design a simple, but effective, modular Peltier heat pump system component to provide chilled or hot water for domestic use at the appliance level, and when arranged in multiple unit combinations, a system that can potentially satisfy small home cooling and heating requirements. Moreover, when the TEs are directly energized using solar PV panels, the system provides a renewable, pollution free and off-the-grid solution to supplement home energy needs. The present work focuses on the design and testing of a thermoelectric heat exchanger component that consists of two water channels machined from two aluminum plates with an array of three or five thermoelectric modules placed in between to transiently cool and/or heat the water in the thermal energy storage tank. The water passing over either the cold or hot side of the TE modules is recirculated to charge the cold or hot thermal storage tank, respectively. The temperatures in the prototype Peltier heat exchanger test component and thermal energy water storage tank were measured during both cold tank charging and hot tank charging operation. The thermal efficiencies of TE heat pump cooling/heating system are reported. The effects of TE power input, number of TE units and rate of fluid flow are studied.

Switched Linear Model of a Stratified Hot Water Tank for Control of Micro-CHP Systems

2019 ◽  
Author(s):  
Trevor Bird ◽  
Catherine Weaver ◽  
Neera Jain
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Waste Heat ◽  
Cell Model ◽  
Internal Heat ◽  
Temperature Inversion ◽  
Hot Water ◽  
Water Tank ◽  
Switched Linear System

Abstract We present a switched linear system approach for modeling the complex nonlinear dynamics associated with temperature inversion occurring in thermally stratified hot water tanks. Such tanks are commonly used for thermal energy storage, particularly in low- to medium-temperature waste heat recovery applications. By separating the influence of temperature inversion from the internal heat transfer between states in the governing differential equations, we paramaterize the nonlinearity using a vector of discrete variables. This vector is then used to define the switching between a set of linear, discrete time models. The proposed switched model is validated against a reduced-order nonlinear model of the thermal energy storage and then integrated with a fuel cell model to capture the dynamics of a micro-combined heat and power system. Simulation results demonstrate the importance that temperature inversion has on the stratification dynamics which in turn has implications for control of such systems.

Experimental Testing of a Thermoelectric-Based Hydronic Cooling and Heating Device With Transient Charging of Sensible Thermal Energy Storage Water Tank

2009 ◽  
Vol 1 (4) ◽  
Author(s):  
Michael J. Kazmierczak ◽  
Sreenidhi Krishnamoorthy ◽  
Abhishek Gupta
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Tank ◽  
Hot Water ◽  
System Component ◽  
Water Tank ◽  
Te Modules

Experiments were performed to charge either cold or hot water thermal energy storage tanks using a heat exchanger equipped with multiple thermoelectric (TE) modules. The primary objective was to design a simple, but effective, modular Peltier heat pump system component to provide chilled or hot water for domestic use at the appliance level, and when arranged in multiple unit combinations, a system that can potentially satisfy small home cooling and heating requirements. Moreover, when the TEs are directly energized using solar photovoltaic (PV) panels, the system provides a renewable, pollution-free, and off-the-grid solution to supplement home energy needs. The present work focuses on the design and testing of a thermoelectric heat exchanger component that consists of two water channels machined from two aluminum plates with an array of three, five, or eight thermoelectric modules placed in between to transiently cool and/or heat the water in the thermal energy storage tank. The water passing over either the cold or hot side of the TE modules is recirculated to charge the cold or hot thermal storage tank, respectively. The temperatures in the prototype Peltier heat exchanger test component and thermal energy water storage tank were measured during both cold and hot tank charging operations. The thermal efficiencies of the TE heat pump cooling/heating system are reported. The effects of the TE power input, number of TE units, rate of fluid flow, and heat sink/source temperature are studied.

Numerical study on the dynamic performance of combined sensible-latent heat packed-bed thermocline tank

2021 ◽  
pp. 1-36
Author(s):  
Elsaeed Elsihy ◽  
Chao Xu ◽  
Xiaoze Du
Keyword(s):  
Energy Storage ◽  
Phase Change Materials ◽  
Volume Fraction ◽  
Numerical Study ◽  
Dispersion Model ◽  
Dynamic Performance ◽  
Packed Bed ◽  
Water Tank ◽  
Total Utilization ◽  
Utilization Ratio

Abstract Thermal energy storage (TES) using thermocline technology with phase change materials (PCMs) is a promising technique for peak shaving operation in cogeneration units. One of the disadvantages of this connotation is the use of the highly-cost PCM capsules in a water tank. To circumvent this issue, a new thermocline tank connotation is proposed. The tank is packed with a mixture of solid filler pills and PCMs capsules, forming a multi-layer packed-bed system. A transient concentric-dispersion model is developed to assess the dynamic performance of a solid-PCM multi-layer packed-bed (SPMLPB) tank. The influences of the PCMs volume fraction (VF) and the charge and discharge dimensionless cut-off temperatures criterion on the dynamic performance have been investigated. The results show that the VF of PCMs influences the system's behavior, both in terms of energy storage and release. As the PCMs volume fraction increases from 10% to 40%, the amount of energy storage, energy release, and latent utilization ratio increased by 82.65%, 73.94%, and 55%, respectively, while the exergy overall efficiency falls by 6.3%. Besides, increasing both the charge and discharge cut-off temperatures (ST*ch/ST*dish) enhances the total utilization ratio and energy recovered. As ST*ch increases from 0.27 to 0.7, total utilization ratio and energy recovered increased by 63.63% and 28.67% respectively by maintains ST*dish = 0.26.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
A. Castell ◽  
C. Solé ◽  
M. Medrano ◽  
M. Nogués ◽  
L. F. Cabeza
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Materials ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Thermal Energy Storage Systems

Most of the thermal energy storage systems available on the market use water as a storage medium. The improvement of the storage efficiency results in a higher performance of the whole system, and thermal stratification is commonly used for this purpose. On the other hand, in applications with small temperature changes, phase change materials (PCMs) provide high energy density since the latent heat is much larger than the sensible heat. This is the case of stratified hot water tanks, where the temperature change in the top layer is small as it is held close to the usage temperature. The benefits of using PCMs in a water tank, in terms of energy storage density, have been demonstrated before. The time with available hot water is increased because of the energy stored in the PCMs. The aim of this work is to demonstrate that the use of PCMs in the upper part of a water tank holds or improves the benefit of the stratification phenomenon. Two tanks with the same dimensions were compared during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water tank (a water tank with a phase change material placed at the top).

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